1、 ISO 2017 Ductile iron fittings, accessories and their joints and valves Epoxy coating Raccords, accessoires et leurs assemblages et appareils de robinetterie en fonte ductile Revtement poxy INTERNATIONAL STANDARD ISO 18468 First edition 2017-06 Reference number ISO 18468:2017(E) ISO 18468:2017(E)ii
2、 ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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4、22 749 09 47 copyrightiso.org www.iso.org ISO 18468:2017(E)Foreword iv 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 1 4 Routine test requirements . 2 4.1 General . 2 4.2 Surface preparation 3 4.3 Coating appearance. 3 4.4 Coating thickness 3 4.5 Adhesion (pull off test/cross cut kn
5、ife test) 3 4.6 Cross linkage (MIBK/Tg) 3 4.7 Non-porosity . 3 4.8 Repairs . 4 5 Performance requirements . 4 5.1 General . 4 5.2 Materials in contact with water intended for human consumption . 4 5.3 Materials in contact with sewage waters . 4 5.4 Impact resistance 4 5.5 Resistance to hot water . 4
6、 6 Test methods . 5 6.1 Routine tests . 5 6.1.1 Surface preparation . 5 6.1.2 Coating appearance . 5 6.1.3 Coating thickness 5 6.1.4 Adhesion (pull off/cross cut knife test) . 5 6.1.5 Cross linkage (MIBK/Tg) . 5 6.1.6 Non-porosity . 5 6.2 Performance test . 6 6.2.1 Impact resistance strength 6 6.2.2
7、 Resistance to hot water 6 Annex A (normative) Quality assurance . 7 Annex B (normative) Cross cut knife test method 9 Annex C (informative) Coating material 10 Annex D (informative) Handling, transportation and storage .11 Bibliography .12 ISO 2017 All rights reserved iii Contents Page ISO 18468:20
8、17(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for whi
9、ch a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all m
10、atters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This
11、 document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any
12、or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents). Any trade name used in this document is information given for the convenience of
13、users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Bar
14、riers to Trade (TBT) see the following URL: w w w . i s o .org/ iso/ foreword .html. This document was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings, Subcommittee SC 2, Cast iron pipes, fittings and their joints.iv ISO 2017 All rights reserved INTERNATIONAL ST A
15、NDARD ISO 18468:2017(E) Ductile iron fittings, accessories and their joints and valves Epoxy coating 1 Scope This document specifies the requirements and test methods applicable to factory applied epoxy coatings (fusion bonded or 2-pack liquid epoxy) for ductile iron fittings and accessories supplie
16、d to ISO 2531 and ISO 7186, and ductile iron valves. It covers internal and external coatings for use in the conveyance of raw water, potable water and waste waters for operating temperatures up to 60 C. This document contains specifications for performance tests and routine tests of the coating. 2
17、Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including a
18、ny amendments) applies. ISO 2531, Ductile iron pipes, fittings, accessories and their joints for water applications ISO 4624, Paints and varnishes Pull-off test for adhesion ISO 7186, Ductile iron products for sewerage applications ISO 8501-1, Preparation of steel substrates before application of pa
19、ints and related products Visual assessment of surface cleanliness Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings ISO 8502-3, Preparation of steel substrates before application of paints and related products
20、Tests for the assessment of surface cleanliness Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method) 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 2531 and the following apply. ISO and IEC maintain ter
21、minological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp 3.1 adhesion pull off test force per unit area, applied perpendicular to the surface
22、, which is necessary to separate the coating from its substrate 3.2 cross linkage chemical reaction between epoxy resin and hardener to form the final cured coating ISO 2017 All rights reserved 1 ISO 18468:2017(E) 3.3 impact resistance energy which a coating can withstand without damage under define
23、d testing conditions 3.4 non-porosity absence of electrical puncture in a high voltage test (holiday test) under defined test conditions 3.5 epoxy coating factory applied coating with either fusion bonded epoxy powder applied by spraying or dipping in a fluidised bed on preheated parts, with or with
24、out post curing, or two-pack liquid epoxy consisting of a base and a catalyst component which are mixed together in the proportion specified by the manufacturer before application 3.6 chalking superficial reaction of epoxy coating (3.5) due to exposure to UV-radiation Note 1 to entry: The process is
25、 confined to the surface only and results in a dulling of the surface. 3.7 performance test test which is done once and thereafter only when there is a change in the coating material or coating process 3.8 routine test test carried out to control the manufacturing process Note 1 to entry: The freque
26、ncy of the test is defined by this document or the manufacturer. 3.9 designated zone area of the casting designated by jointing/mating surfaces or process and test characteristics where a lower coating thickness standard is applied EXAMPLE 1 An example of jointing/mating surfaces is joint areas. EXA
27、MPLE 2 Examples of process and test characteristics are bolt holes, marking, ribs, edges. 3.10 localised thickness measured thickness at any one point of one coated product 4 Routine test requirements 4.1 General The following technical requirements shall be demonstrated by routine tests applied in
28、production, on in-process and finished coated products with defined frequency. Routine tests shall be in accordance with the overview of requirements provided in Table A.2. Annex D outlines the handling, transportation and storage of coated products.2 ISO 2017 All rights reserved ISO 18468:2017(E) 4
29、.2 Surface preparation Prior to coating application, all surfaces to be coated shall be blasted to be substantially clean and free from oil, grease and moisture. The surfaces to be coated shall meet the requirements of Class Sa 2.5 of ISO 8501-1 and Rating 3 dust quantity of ISO 8502-3. Blasted fitt
30、ings and accessories shall only be handled and stored, using tested methods to maintain Sa2.5 finish without any visible rusting and contamination, until coating application. 4.3 Coating appearance The epoxy coating of the final product shall be of uniform colour, except for permitted marking; unifo
31、rm appearance and smoothness, except for allowable repairs; free of visible defects (i.e. pinholes, bubbles, blisters, wrinkles, cracks or voids). Slight superficial colour variations due to repairs or long exposure to sunlight (chalking) are permissible. 4.4 Coating thickness When measured in accor
32、dance with the method defined in 6.1.3, except on the designated zones, the localized minimum thickness shall be greater than 200 m and the minimum average thickness shall be greater than or equal to 250 m. For the designated zones, a localized minimum thickness of 150 m is allowed. 4.5 Adhesion (pu
33、ll off test/cross cut knife test) Adhesion (pull off test) shall be tested in accordance with the test method defined in 6.1.4 on production samples. The epoxy coating adhesion shall achieve an average value of at least 8,0 MPa and a minimum single value of 6,0 MPa. The manufacturer shall determine
34、the test locations on the products. Alternatively, the adhesion test can also be done by cross cut knife test method. Where the cross knife test is chosen for adhesion, it shall be carried out according to Annex B. The epoxy adhesion rating shall be no more than level 2. 4.6 Cross linkage (MIBK/Tg)
35、When tested in accordance with the test method defined in 6.1.5, after wiping with an MIBK solution, the cloth and the coating surface shall be visually examined. Any discolouration, matting and/or smearing observed shall not exceed the limits specified by the coating manufacturer. Alternatively, th
36、e cross linkage of coating can be determined by its change in glass transition temperature (Tg) and Tg shall be no more than 5 C. 4.7 Non-porosity When tested in accordance with the test method described in 6.1.6, with a voltage of 1 500 V, the coated body of the product shall be free from porosity.
37、 This means that no electrical puncture should occur. This requirement does not apply to designated zone. ISO 2017 All rights reserved 3 ISO 18468:2017(E) 4.8 Repairs Repairs shall be carried out when there is a fault. The fault can be localized damage, holding point, earthing surface for the non-po
38、rosity test, or other coating fault. The coating manufacturer should establish the repair procedure. The material to be used shall satisfy two conditions: be suitable for protecting fittings and accessories under the required service conditions; be compatible in all aspects with the previously appli
39、ed epoxy coating. The repairs shall comply with the requirements specified in 4.4, 4.6, and 4.7. 5 Performance requirements 5.1 General The following technical requirements shall be demonstrated by performance tests, in order to verify the coating material and process prior to production coating. Pe
40、rformance tests shall be in accordance with the overview of requirements provided in Table A.1. Annex C provides the requirements of the coating material. A.2 defines the DN grouping of performance tests. Where there is a change of coating material or process, the performance tests shall be undertak
41、en on the new coating material or process. 5.2 Materials in contact with water intended for human consumption When used under the conditions for which they are designed, in permanent or in temporary contact with water intended for human consumption, the coating shall not have any detrimental effects
42、 on the properties of that water for its intended use. When used for conveying water intended for human consumption, the coating materials in contact with the water shall meet the relevant requirements of the national standards or regulations in the country of use with respect to effect on water qua
43、lity. 5.3 Materials in contact with sewage waters The coatings shall comply with requirements of chemical resistance and abrasion resistance, defined in ISO 7186. If needed, the chemical resistance test can be performed at pH 1 by agreement between manufacturer and purchaser . 5.4 Impact resistance
44、When tested in accordance with the test method described in 6.2.1, no holidays shall be permitted. 5.5 Resistance to hot water When tested in accordance with test method specified in 6.2.2, the coating adhesion shall meet a minimum requirement of 6,0 MPa. In addition, on visual examination there sha
45、ll be no cracks, wrinkles, disbondment or blisters.4 ISO 2017 All rights reserved ISO 18468:2017(E) 6 Test methods 6.1 Routine tests 6.1.1 Surface preparation The blasted surface of the product shall be visually checked for its compliance, and shall at least meet the requirements of Class Sa 2.5, as
46、 specified in ISO 8501-1, and Rating 3 and Class 2 as specified in ISO 8502-3. 6.1.2 Coating appearance The appearance of the finished coating shall be checked visually. 6.1.3 Coating thickness The thickness of the coating shall be measured with a non-destructive instrument (e.g. magnetic or electro
47、-magnetic type) with measuring accuracy of at least 1 %. 6.1.4 Adhesion (pull off/cross cut knife test) Adhesion (pull off/cross cut knife) shall be defined on surfaces of a coated product, or coated test plates (if more convenient). The test plates should be manufactured of identical material and c
48、oated by the identical process. In order to properly test the adhesion of the coating to the surface, the test areas shall be selected in such a way that the coating thickness is no less than 250 m. Pull off test shall be conducted as specified in ISO 4624. If fracture is only associated with the ad
49、hesive and the result is less than 8,0 MPa, the test may be deemed as a no-test, and another test should be performed with a suitable adhesive for the epoxy coating. Cross cut knife test shall be carried out according to Annex B. 6.1.5 Cross linkage (MIBK/Tg) The test shall be conducted using methyl isobutyl ketone (MIBK). On a dust-free coated product, a clean white cloth dipped in MIBK shall be rubbed repeatedly on the surface over an area of at least 16 cm 2for a period of 30 5 s. The colo
